Self-locking pile joint

ABSTRACT

TWO PILES ARE JOINED TOGETHER BY INTERFITTING MEANS IN THEIR OPPOSED ENDS. ONE PILE HAS A TUBE EMBEDDED THEREIN, THE TUBE HAVING ONE, OPEN, END FLUSH WITH THE END FACE OF THE PILE AND ITS OTHER END BEING FLARED AND CLOSED. THE OTHER PILE HAS A ROD WHOSE END IS CUT PROJECTING FROM IT. THE ROD IS PLACED IN THE TUBE AND AS THE PILE IS DRIVEN THE CUT END IS FORCED BY A WEDGE INTO THE FLARE OF THE TUBE, THUS LOCKING THE PILES TOGETHER.

Dec. 7, 1971 s. THORBURN SELF-LOCKING PILE JOINT 2 Sheets-Sheet 1 FiledNdv. 19, 1969 i v... 01 u .0 b A. v ma I l I. o a n 4 In ver llor SAMUELfimmumv Attorneys Dec, 7, 1971 s. THORBURN 3,625,012

I SELF -LOCKING PILE JOINT Filed Nov. 19, 1969 2 Sheets-Sheet 2 Inventor 6Z4 MUEL 7 /025 ue/v Attorney! United States Patent 3,625,012SELF-LOCKING PILE JOINT Samuel Thorburn, Glasgow, Scotland, assignor toLogistics Limited, Great Britain Filed Nov. 19, 1969, Ser. No. 878,056Claims priority, application England, Feb. 4, 1969, 6,059/ 69; May 22,1969, 26,064/ 69 Int. Cl. E02b /30; E04b 1/48 US. Cl. 61-56 12 ClaimsABSTRACT OF THE DISCLOSURE Two piles are joined together by interfittingmeans in their opposed ends. One pile has a tube embedded therein, thetube having one, open, end flush with the end face of the pile and itsother end being flared and closed. The other pile has a rod whose end iscut projecting from it. The rod is laced in the tube and as the pile isdriven the cut end is forced by a wedge into the flare of the tube, thuslocking the piles together.

This invention relates to a self-locking joint in piles.

The length of a single pile is limited by the need to transport it,raise it into position for driving, and so on. There is thus a need fora means of joining piles together to allow piling to a depth greaterthan the length of a single pile.

An object of the present invention is to provide an improved pile joint.

The present invention is a self-locking pile joint including first andsecond piles having cooperating end faces, a rod having one end embeddedin the pile and a second, sa'w-cut end projecting from the end face ofthe first pile, a tube communicating at one end with said end face ofthe second pile, embedded in the second pile and being at its other endflared and closed, and a wedge member for engagement with the saw-cutend of the rod and with the closed end of the tube, the rod and tubeinterfitting and the wedge member splitting the saw-cut end of the rodto secure and wedge together the two piles.

Embodiments of the present invention will now be described, by way ofexample, with reference to the accompanying drawings, in 'which:

FIG. 1 is a sectional elevation of a pile joint according to the presentinvention;

FIG. 2 is a sectional elevation of a. second embodiment before the jointis made;

FIG. 3 is a view similar to FIG. 2 but showing the finished joint; and

FIG. 4 is a section on A-A of FIG. 2.

Referring now to FIG. 1, two precast concrete piles 10, 11 prestressedby wires 22 are located end-to-end, a thin layer of jointing material 12being inserted between cooperating end faces a, 11a. The jointingmaterial is, of course, capable of withstanding the stresses of piledriving and serves to absorb irregularities in the end faces 10a, 11a. Abituminous-impregnated asbestos material may be used.

One pile, in this embodiment the upper pile 10, has one end of a rod 13cast into it, abutting a metal plate also cast into the pile. The otherend of the rod 13 projects from the pile 10, and this end has a singlediametrical saw-cut through it. The plate 15 assists in bonding the rod13 into the pile 10.

The other pile 11 has a metal tube 14 embedded in it, one end of thetube being flush with the end face 11a of the pile 11. The other end ofthe tube 14 is flared and closed by a closure 16 and the closure 16supports an upstanding wedge member 17 which is, in this embodiment, thesame length as the flare of the tube 14. The rod 13 and tube 14interfit.

The embodiment shown in FIGS. 2 to 4 is similar to that of FIG. '1, andsimilar parts are denoted by like reference numerals. In thisembodiment, however, the rod 13 is modified in that two, mutuallyperpendicular saw cuts 18, 19' through it, each saw-cut terminating inone of two mutually perpendicular holes 20, 21 drilled through the rod13, the holes 20, 21 being normal to the longitudinal axis of the rod13. The holes 20, 21 reduce the possibility of the saw-cuts 18, 1-9elongating under piling pressure since the stress concentration at theirinternal ends is reduced by providing a smooth-curved surface. In thisembodiment, the wedge member 17 is of circular cross-section.

In use, the lower pile 11 is driven to a suitable depth. The other pile10 is then positioned with the rod 13 projecting into the tube 14 and isdriven in the normal way, this action forcing the saw-cut or cuts overthe wedge member 17 to lock the piles together. The wedge 17 may eitherbe previously fixed to the closure 16 or may be inserted in the cut orcuts before the pile 10 is driven.

Various modifications may be made to the embodiments described above.

The rod and tube are preferably circular in crosssection, but othershapes may be used. The rod may also be replaced by an elongated hollowmember, and the work rod is used herein and in the claims as includingsuch a member.

The metal plate 15 may be dispensed 'with, in which case bonding betweenthe rod and the pile may be assisted by indenting the surface of the rodwhich is enclosed by the pile, or by suitably increasing the enclosedlength of the rod.

Although one rod-and-tube combination is used in the embodimentsdescribed, it will be apparent that a number of such combinations maycooperate to join a pair of piles.

Tlhe rod, tube and plate may suitably be of mild stee The application ofthe present invention is not limited to concrete piles, but appliesequally to piles of, for example, timber and steel.

I claim:

1. A composite pile comprising first and second constituent piles eachmade of reinforced concrete and arranged end-to-end, opposed end faceson said constituent piles, and a rigid and tension-resistant jointconnecting said constituent piles and maintaining said end faces inabutting relationship; said joint comprising a metal spigot extendingaxially of and anchored within said first constituent pile andprojecting outwardly from said end face of the latter, means in thesecond constituent pile defining a socket extending internally andaxially thereof and terminating at its outer end at said end face of thesecond constituent pile, and said means defining also a base closing thesocket at its free end and forming laterally splayable locking sections;and a wedge member abutting said base of the socket, wedgingly engagingbetween said looking sections, and laterally splaying the latter intolocking engagement with the means defining the socket.

2. A pile as claimed in claim 1, wherein said cavitydefining means is atube embedded in said second pile and having a closure for supportingsaid wedge member at the end of the tube remote from the end face ofsaid second pile.

3. A pile as claimed in claim 2, wherein the end of the tube forsupporting the wedge member is outwardly flared so as to enlarge thecavity only in the vicinity of the wedge member.

4. A pile as claimed in claim 1, wherein said cavity defining means is atube embedded in said second pile and is outwardly flared so as toenlarge the cavity only in the vicinity of the wedge member.

5. A pile as claimed in claim 1 in which the spigot anchored in saidfirst pile abuts a metal plate embedded in said first pile.

6. A pile as claimed in claim 1, including first and second mutuallyperpendicular diametrically-disposed slots in said spigot, said Wedgemember being circular in cross section.

7. A pile as claimed in claim 6, wherein the bottom of each slot has asmooth-curved surface to relieve stress concentration.

8. A pile as claimed in claim 1, including a jointing material insertedbetween the end faces of the two piles.

9. A pile as claimed in claim 8, in which the jointing material is of abituminous-impregnated asbestos material.

10. A pile as claimed in claim 1, in which the spigot is of circularcross section.

11. A method of forming a jointed composite reinforced concrete pilecomprising casting a first constituent reinforced concrete pile with anend abutment face and with an axial socket closed at its inner end andterminating at its outer end at said end abutment face; casting a secondconstituent reinforced concrete pile with an end abutment face andanchoring one end of a cold-deformable metal rod in said secondconstituent pile with its other end projecting axially outwardly fromsaid abutment face forming a spigot, forming an axial slot in the end ofsaid spigot, inserting said spigot into said socket until said end facesof the constituent piles are in abutment and laterally splaying theslotted end of said spigot by wedging until said end grippingly abutsthe Wall of the socket.

12. The method according to claim 11, including the step of insertingadhesive between the end faces of the constituent piles prior to theirbeing brought into abutment.

References Cited UNITED STATES PATENTS 736,891 8/1903 Stempel 61-541,340,397 5/1920 Nagel 6156 2,065,507 12/1936 Alexander 6156 3,438,6594/1969 Waldron 287127 R FOREIGN PATENTS 747,969 1933 France 287124436,041 1935 Great Britain 287-124 13,232 1924 Netherlands 6153 JACOBSHAPIRO, Primary Examiner US. Cl. X.R. 287124, 127

